Why do we need vitamin B12?

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 Vitamin 12 is an essential nutrient that plays a key role in several bodily processes.

Benefits of B12 

It is essential for the proper production of red blood cells, DNA production, nerve function and the proper functioning of metabolism .

Vitamin B12 also plays a key role in lowering the level of an amino acid called homocysteine, the high levels of which are associated with chronic diseases such as heart disease, stroke and Alzheimer’s disease .

In addition, vitamin B12 is important for energy production. However, there is currently no evidence that taking vitamin B12 supplements increases energy levels in people who have enough of this nutrient .

Vitamin B12 is found mainly in animal products, including meat, seafood, dairy products and eggs. It is also added to some processed foods, such as cereals and  vegetable milks .

Because your body can store B12 for several years, severe B12 deficiency is rare, but up to 26% of the population may experience a mild deficiency. Over time, vitamin B12 deficiency can lead to complications such as anemia, nerve damage, and fatigue.

 Vitamin B12   deficiency can be caused by insufficient dietary intake of this vitamin, problems with its absorption or the use of drugs that interfere with its absorption .

The following factors may increase the risk of insufficient intake of vitamin B12 from the diet 

  • if you only eat vegetarian or vegan food
  • if you are over 50 years old
  • if you have gastrointestinal disorders including Crohn’s disease and celiac disease
  • if you have had gastrointestinal surgery, such as weight loss or bowel resection
  • if you are taking metformin and medicines to reduce acidity
  • if you have specific genetic mutations such as MTHFR, MTRR and CBS
  • if you regularly consume alcoholic beverages


If you are at risk for deficiency, a  diet  rich  in  B12 or taking supplements can help meet your needs.



 experts do not recommend supplementing vitamin B12 to healthy people in this age group.

Vitamin B12 supplementation is not recommended for healthy people. However, if you have any of the above factors that interfere with your vitamin B12 intake or absorption, you may want to consider taking the supplement.


Adults over 50 years and vitaminB12

Older people are more prone to vitamin B12 deficiency. While younger adults suffer from vitamin B12 deficiency relatively little, up to 62% of adults over the age of 65 have lower levels of this nutrient in their blood than would be appropriate for their body ).

As you age, your body naturally produces less stomach acid and intrinsic factor, which can affect the absorption of vitamin B12.

Gastric acid is needed to access vitamin B12, which is naturally found in food, and an intrinsic factor is needed to absorb it.

In view of this increased risk of insufficient absorption, the National Academy of Medicine recommends that adults over the age of 50 cover most of their vitamin B12 needs through supplements and fortified foods  .  

One 8-week study of 100 elderly adults found that supplementation with 500 μg of vitamin B12 normalized B12 levels in 90% of participants. Higher doses of up to 1,000 μg (1 mg) may be required in some patients  .  


Pregnant women and B12

Pregnant women have a slightly higher need for vitamin B12 than the general population.

Low levels of this vitamin in mothers are associated with birth defects in children    

In addition, a large systematic review has shown that vitamin B12 deficiency is associated with a higher risk of preterm birth and low birth weight infants  

Therefore, the recommended daily dose for vitamin B12 during pregnancy is 2.6 μg. This level can be reached by diet alone or by prenatal vitamin  


Breastfeeding women and B12

Vitamin B12 deficiency in breast-fed infants is associated with delayed development  

In addition, vitamin B12 deficiency in infants can lead to irritability, decreased appetite, and failure to thrive  .



Vegetarians and vegans and B12

The recommendations for vitamin B12 do not differ between people who eat a plant-based diet.


A review of 40 studies on vitamin B12 in vegetarians found that up to 86.5% of adult vegetarians – including older adults – have low levels of vitamin B12  

There are currently no government recommendations for dosing B12 supplements for vegetarians.

However, one study suggests that doses of up to 6 μg of vitamin B12 per day may be appropriate for vegans  


Dosage of B12 to increase energy

Although vitamin B12 is commonly used to increase energy levels, there is no evidence that B12 supplements increase energy levels in humans without a deficiency.

However, B12 supplements have been found to increase energy levels in those who are deficient in this nutrient  .


People who have problems absorbing vitamin B12, such as people with Crohn’s disease or other gastrointestinal problems, can use  vitamin  B12  injection to avoid the need for gastrointestinal absorption 


B12 for memory and mood

It is generally believed that taking vitamin B12 can improve your memory and mood. However, there is not much evidence to support this theory.

Animal studies suggest that vitamin B12 deficiency is associated with memory impairment. However, there is currently no evidence that B12 supplements improve memory in people with a deficiency .

A large review of studies has shown that vitamin B12 supplements do not have a short-term effect on depressive symptoms, but can help prevent relapse in the long term  .

So far, there are no specific dosing recommendations for B12 supplements for mental performance or mood.


Possible side effects

Vitamin B12 is a water-soluble vitamin, which means that what you do not need is excreted in the urine by your body.

Because vitamin B12 is relatively safe, no upper tolerable intake limit (UL) has been established for it. UL is considered to be the maximum amount of a substance that can be used safely without side effects.

However, in some cases, vitamin B12 has been shown to cause rare side effects.

   can lead to skin diseases such as acne and dermatitis (rash)  

High doses of B vitamins above 1,000 μg have also been associated with complications in people with kidney disease  

In addition, extremely high levels of vitamin B12 in mothers’ blood have been associated with a higher risk of autism in their children  .


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